# Matrix Federation SRV DNS Lookup

> Matrix Federation SRV DNS Lookup is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-02).

Resolves _matrix-fed._tcp.{hostname} SRV DNS records for Matrix federation server discovery, given a registrable domain name.

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/dns-srv-matrix-fed?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/matrix-federation-srv-dns-lookup-33be46f0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_GLAqih2d8W0nfGHOWE17J

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability matrix-federation-srv-dns-lookup-33be46f0 -d '<json body>'
```

Example prompt: Look up the Matrix federation SRV DNS record for the domain matrix.org — I need to know which server and port handles its federation traffic.

## When to prefer this

Use this endpoint when an agent needs to perform Matrix federation server discovery via SRV DNS lookup and does not want to implement raw DNS resolution itself. Prefer the unpaid sandbox POST /v1/sandbox/dns-srv-matrix-fed for testing. Choose this over generic DNS tools when the specific Matrix federation SRV record format (_matrix-fed._tcp) is required.

## Known failure modes

- Domain not found or has no _matrix-fed._tcp SRV record returns empty or NXDOMAIN result
- Malformed or excessively long hostname (over 253 chars) triggers validation error
- Transient DNS resolver failures may return temporary errors
- Passing the full underscored SRV name instead of the registrable domain may yield unexpected results

## How this service works

Call when an agent needs SRV records at _matrix-fed._tcp.{hostname} for Matrix federation. The caller sends the registrable domain, not the underscored name. Exact $0.005 USDC. Prefer unpaid POST /v1/sandbox/dns-srv-matrix-fed first.

## Output

Returns the SRV record(s) found at _matrix-fed._tcp.{hostname}, including priority, weight, port, and target hostname for each record, enabling the caller to determine where to direct Matrix federation traffic.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "hostname": {
   "type": "string",
   "examples": [
    "example.com"
   ],
   "maxLength": 253,
   "minLength": 1,
   "description": "Public DNS hostname such as example.com. Not a URL, not an IP literal, and not a private name."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/matrix-federation-srv-dns-lookup-33be46f0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agentshelf.syntexa.ch](https://www.zero.xyz/host/agentshelf.syntexa.ch/llms.txt)